The OPs 05 Passat is actually a PD engine and requires the VW 505.01 oil. There are many people that ran them on Mobil TDT 5w40 or Rotella T6 5W40 both synthetic with success but that is at your own risk. I def wouldn't run a conventional 15w40 in that engine at all. They do have a spec for a reason, and having an engine with known problems makes it risky to just use anything off the shelf in it. Just mentioning it in case you didn't know. By now any stickers under the hood mentioning this have probably fallen off.
Originally Posted by LoneRanger
Wasn't that was mainly on the old PD (pumpe deuse, i.e. unit injectors) motors? The individual high pressure injectors were driven off the cam lobes and this caused excessive wear to that area. Actually a lot of people who are enthusiasts for the TDI VW's over on Fred's TDIClub forum dropped the VW spec oil and ran either Mobil 1 Turbo Diesel Truck 5W40 or Rotella T6 5W40 which were showing in repetitive oil analyses to yield lower metal wear than the VW spec oil. 505.01, that's the spec I couldn't remember in my post above. And if memory serves, I think 507.00 was eventually approved by VW for the PD engines. 507.00 was the spec for the 2006 and newer model TDI's at the time when they came out, which had a different injector and fuel pump setup. At about 60,000 miles on my 1st wife's Beetle TDI I switched it to Mobil 1 Turbo Diesel Truck 5W40 and eventually for lower cost switched it to Rotella T6 5W40. It had 105,000 miles on it when it was sold in 2012 and the motor was perfect except the intake needed a cleaning (another issue on the pumpe deuse motors due to EGR and oily soot). It was bought by an enthusiast on Fred's TDI Forum who was knowledgeable about that gen of TDI and ready to do the intake cleaning. Intake cleaning was a disassembly process involving complete removal of the intake manifold and immersion in solvent, if I remember right.
Originally Posted by ragtoplvr
DO NOT USE THE WRONG OIL on VW Diesels. They need the correct vw spec oil because of the weird fuel injection, the wrong stuff will wear the cam shaft. Rod